There is however a noticeable slump in the final act. The factual basis of the material often ties the film down and prevents it from realising the dramatic potential of The Departed or The Town.

It must be said that as Bulger’s powerful diplomat brother, Benedict Cumberbatch fails to convincingly pahk his cah in hahvahd yahd, but the rest of the supporting cast (including Kevin Bacon and Jesse Plemons) are terrific. Besides, this is Johnny’s gig, and he is utterly terrifying. He brings an unpredictable, savage intensity to the role that is mesmerising. It’s a pleasant surprise to see Depp acting again, because he’s rather good at it. With sequels to Alice in Wonderland and Pirates of the Caribbean on the horizon, perhaps we shouldn’t get used to the idea.